Refrigeration method and apparatus

ABSTRACT

1,156,148. Refrigerators. CHEMETRON CORP. 27 Sept., 1966 [22 Oct., 1965], No. 43033/66. Heading F4H. Liquefied gas is evaporated in heat exchangers 31, 33 and the vapour is passed into a first network of longitudinally spaced ducts 30, 32, 40, 44 formed about the storage compartment 28 of an insulated container, the vapour then passing to a second network of ducts 45, 46, 49, 50, 53, 54 adjacent the external casing of the container before being vented to atmosphere. Headers 36, 37, 39, 41, 43, 47, 48, 51, 52, 55 interconnecting the ducts are provided. Heat exchangers 31, 33 are arranged to discharge into alternate ones of the ducts 32 in counterflow. The internal surfaces of the external casing may be lined with insulation and this in turn may be lined with material of good thermal conductivity.

Feb 1967 c. F. FRITCH, JR

REFRIGERATION METHOD AND APPARATUS Filed 001;. 22, 1965 l rfilflflfillll rllll Iifllflllllllllll: illllllivlwll Inventor Carl F. Fricclmdr, Mu/

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United States Patent 3 303 659 REFRIGERATION METI-IOD AND APPARATUS Carl F. Fritch, Jr., Glen Ellyn, Ill., assignor to Chemetron Corporation, Chicago, Ill., a corporation of Delaware Filed on. 22, 1965, Ser. No. 501,982 2 Claims. 01. 62-45) This invention relates to a method of refrigeration which is particularly adapted to use cold liquefied gas as a refrigerant and to apparatus for carrying out the method.

The prime object of the invention is to provide a method, and apparatus for carrying out the method, by which heat is withdrawn from a compartment by vaporization of cold liquefied gas and/or its vapor, and

in which the vapor is thereafter passed through a network of spaced apart flow paths externally of insulation surrounding internal wall structure forming the compartment to intercept heat from ambient air to prevent such heat from entering the compartment.

In accordance with the method of the invention, cold liquefied refrigerant gas such as liquid nitrogen or liquid carbon dioxide is vaporized by heat exchange with a compartment formed by internal wall structure. A network of spaced apart flow paths are formed so as to be in heat exchange relationship with a substantial part of the internal wall structure, and a second network of spaced apart fiow paths formed in the insulation adjacent the external wall structure. The resultant vapor is passed at spaced apart locations directly into and through the first network of spaced apart flow paths and thereafter through the second network of spaced apart flow paths. The spent vapor is vented out of the second network of flow paths to the atmosphere.

In the drawings:

FIGURE 1 is a fragmentary top plan view, partly in section of apparatus for carrying out the invention;

FIGURE 2 is a sectional view taken along line 22 of FIGURE 1;

FIGURE 3 is a sectional view taken along line 3-3 of FIGURE 1;

FIGURE 4 is a horizontal sectional fragmentary view showing in particular passages in the floor and a side wall;

FIGURE 5 is a fragmentary sectional view showing an alternative embodiment of the invention; and

FIGURE 6 is a fragmentary sectional view showing another alternative embodiment of the invention.

Referring now to the embodiment of FIGURES 1 through 4 of the drawings, there is shown refrigeration apparatus generally indicated at having internal Wall structure indicated 'at 21 having a ceiling 22 and a floor 23 joined by four walls 24. Spaced outwardly of the internal wall structure 21 is external wall structure or jacketing 26. Insulation 27 disposed between the internal and external wall structures 21 and 26 serves to prevent heat transfer into a compartment 28 formed by the internal wall structure 21. A suitable closure (not shown) provides access to the compartment 28 where the cargo (not shown) can be placed.

A network of passages generally indicated at 29 is shown to include passages 30 which communicate with a vaporizer 31 and passages 32 which communicate with a vaporizer 33. The passages 30 and 32 are disposed in an alternating, parallel, horizontal arrangement so that fiow of vapor in adjacent passages 30' and 32 is in opposite directions. At least the part of the internal wall structure adjacent the network of passages 29 is composed of material capable of efficient heat transfer such as aluminum, for example the ceiling 22, the floor 23 and two opposite walls 24.

A cylinder or other suitable container (not shown) for storing cold liquefied gas is connected to the vaporizers 31 and 33 which vaporize the cold liquefied gas and pass the resultant vapor into passages 30 and 32, respectively. The passages 30 extend to and partially around the vaporizer 33 and communicate with a common header 36, while the passages 32 extend to and partially around the vaporizer 31 and communicatewith a common header 37. Substantially vertically extending, parallel passages 30 communicate at their upper ends with the header 36 and at their lower ends with a comomn header 39, while vertically extending, parallel passages 40 communicate at their upper ends with a header 37. Parallel horizontal passages 42 communicate with the header 39 and a header 43, while parallel horizontal passages 44 com- .municate with the header 41 and the header 43. The

header 37 communicates with passages 45 and 46 which in turn communicates with headers 47 and 48 respectively. Passages 49 and 50 communicate with headers 47 and 48 and headers 51 and 52, respectively. Passages 53 and 54 communicate with headers 51 and 52 and a header 55, respectively. The header 55 communicates with an exhaust port 56 which opens to the atmosphere, The outer network of passages 29' from the header 43 to the header 55 are formed in part by the insulation 27 and in part by external wall structure or jacketing 26.

Each vaporizer 31 and 33 includes a conduit 57 disposed inside a larger conduit 58. The conduit 57 is connected to the cylinder (not shown) and has orifices (not shown) by which cold liquefied gas is metered into the conduit 58. Conduits 58 of Vaporizers 31 and 33 have orifices (not shown) which communicate with passages 30 and 32 respectively.

In operation, vapor formed in the vaporizer 31 which is in heat exchange relationship with the compartment 28 and, in fact, in direct heat exchange relationship with the ceiling 22, passes through passages 30 in heat exchange relationship with the ceilings, into heat exchange relationship with the vaporizer 33, into the header 36, into the passages 38, into the header 39, into the passages 44 to the header 43. Vapor formed in the vaporizer 33 which is in heat exchange relationship with the compartment 28 and in direct heat exchange relationship with the ceiling 22, passes through passages 32 in heat exchange relationship with the ceiling 22, into heat exchange relationship with the vaporizer 31, into the header 37, through the passages 40 and into the header 41, and into and through passages 44 and into the header 43. The temperature of the vapors in the header 43 can be at least equal to and perhaps even slightly higher than the temperature of the compartment 28. As the temperature of the compartment 28 is substantially lower than the ambient air surrounding the container 20, there is still a substantial difference between the temperature of the vapor in the header 43 and the ambient air, even though all of the latent cooling power and a substantial part of the sensible cooling power of the refrigerant such as nitrogen or carbon dioxide has been used up by the time its vapor has reached the header 43. The vapor in the header 43 passes to passages 45 and 46, to the headers 47 and 48, to the passages 49 and 50, into the headers 51 and 52, to passages 53 and 54, respectively, and into the common header 56 from which the spent vapor is exhausted through the port 56. The spent vapor passing out through the port 56 can be at the temperature of the ambient air.

The embodiment of FIGURE 5 is similar to the embodiment of FIGURES 1 through 4 and hence the same reference characters are used, with the addition of letter a to designate the same components. In the embodiment of FIGURE 5, the inside surface of the external wall structure or jacketing 26a is covered with insulation 60 which can be applied in a number of Ways, for example by flocking or by adhering sheet insulation to the inside surface of the jacketing 26a. Thus, the vapors can exert a heat shielding effect throughout the outer network of spaced apart passages from the header 43 to the header 55. In all other respects the embodiment of FIGURE 5 is the same as the embodiment of FIGURES 1 through 4. The passages 49a, 53a and so forth are formed in part by the insulation 27a and in part by the insulation 60.

The embodiment of FIGURE 6 is similar to the embodiment of FIGURES 1 through 4 and hence the same reference characters are used, with the addition of letter b to designate the same components. In the embodiment of FIGURE 6, the inside surface of the external wall structure or jacketing 26b is covered with insulation 61 which can be applied as described in connection with FIGURE 5. The inside surface of the insulation 61 is covered with a layer of material 62 capable of efiicient heat transfer, such as aluminum particles or aluminum sheet or foil. The layer of heat conductive material 62 thus distributes cold so as to form a heat shield. The outer network of passages 49]), 53b and so forth is thus formed in part by the insulation 27b and in part by the material 62.

Other embodiments and modifications of this invention will suggest themselves to those skilled in the art, and all such of these as come within the spirit of this invention are included within, its scope as best defined by the appended claims.

I claim:

1. Method of refrigerating a container having internal wall structure forming a compartment and surrounding external wall structure, with insulation disposed between the internal and external wall structures, comprising the steps of: forming a network of spaced apart flow paths spaced from said internal wall structure and disposed adjacent said external wall structure, passing vapor of cold liquefied gas in heat exchange relation with the compartment, thereafter passing the vapor through the network of passages, and venting spent vapor from the network of passages to the atmosphere.

2. Method of refrigerating a container having internal Wall structure forming a compartment and surrounding external wall structure, with insulation disposed between the internal and external wall structures; comprising the steps of: forming a first network of spaced apart flow paths in heat exchange relationship with a substantial part of the internal wall structure, forming a second network of spaced apart flow paths in the insulation adjacent the external wall structure, isolating the first and second networks of fiow paths from the space within the compartment, vaporizing cold liquefied gas 'by heat exchange with the internal wall structure, passing the resultant cold vapor at spaced apart locations directly into and through the first network of spaced apart flow paths and thereafter through the second network of spacerd apart flow paths, and venting vapor out of the second network of flow paths to the atmosphere.

References Cited by the Examiner UNITED STATES PATENTS 966,076 8/1910 Bobrick. 2,576,665 11/1951 Bixler 62-405 X 3,096,626 7/1963 Morrison 62-60 3,127,755 4/1964 Hemery 62-267 LLOYD L. KING, Primary Examiner. 

1. METHOD OF REFRIGERATING A CONTAINER HAVING INTERNAL WALL STRUCTURE FORMING A COMPARTMENT AND SURROUNDING EXTERNAL WALL STRUCTURE, WITH INSULATION DISPOSED BETWEEN THE INTERNAL AND EXTERNAL WALL STRUCTURES, COMPRISING THE STEPS OF: FORMING A NETWORK OF SPACED APART FLOW PATHS SPACED FROM SAID INTERNAL WALL STRUCTURE AND DISPOSED ADJACENT SAID EXTERNAL WALL STRUCTURE, PASSING VAPOR OF COLD LIQUEFIED GAS IN HEAT EXCHANGE RELATION WITH THE COMPARTMENT, THEREAFTER PASSING THE VAPOR THROUGH THE NETWORK OF PASSAGES, AND VENTING SPENT VAPOR FROM THE NETWORK OF PASSAGES TO THE ATMOSPHERE. 